Diagnostic criteria for dengue fever, dengue haemorrhagic fever, and dengue shock syndrome.

Dengue Fever

An acute febrile illness of 2-7 days duration with two or more of the following manifestations:
1) Headache
2) Retro-orbital pain
3) Myalgia
4) Arthralgia
5) Rash
6) Haemorrhagic manifestations

Dengue Haemorrhagic Fever

1) A probable or confirmed case of dengue
2) Haemorrhagic tendencies evidenced by one or more of the following: a) Positive tourniquet test b) Petechiae, ecchymoses or purpura c) Bleeding from mucosa, gastrointestinal tract, injection sites or other sites d) Haematemesis or malena
3) Thrombocytopenia (<100,000 cells per cumm)
4) Evidence of plasma leakage due to increased vascular permeability, manifested by one or more of the following : a) A rise in average haematocrit for age and sex > 20% b) A more than 20% drop in haematocrit following volume replacement treatment compared to baseline c) Signs of plasma leakage (pleural effusion, ascitis, hypoproteinaemia)

All the above criteria for DHF plus evidence of circulatory failure manifested by rapid and weak pulse and narrow pulse pressure (<20 mm Hg) or hypotension for age, cold and clammy skin and restlessness.